Manufacture of an elastic cellular or spongy material for use as a filling for vehicle-tires, cushions, buffers, upholstery, and the like.



- UNITED srA Es PATENT omen FRITZ PFLEUMER OF-DRESDEN, GERMANY, ASSIGNOR TO PFLEUMATIG SYNDICATE LIMITED,

OF LONDON, ENGLAND, A CORPORATION OF GREAT BRITAIN.

MANUFACTURE OF AN ELASTIC CELLULAR OR SPONGY MATERIAL FOR USE AS A FILL- ING FOB VEHICLE-TIRES, CUSHIONS, B'UFFERS, UPHOLSTERY, AND THE LIKE.

No Drawing.

. spongy material for use as an elastic filling for hollow vehicle-tires, cushions, seats, mattresses, balls, bufl ers, elastic saddles, ships fenders, upholstery, and the like.

' The improved process depends on the well known fact that sheets of gelatin, which have been left for some days in a solution of pyrogallol, with access of air, are quite insoluble after drying. This fact is however not directly available for the purpose in view, as one cannot leave the mass of glycerin and gelatin in a pyrogallol-solution to soak and then dry it. The pyrogallol must rather beadded in aqueous or alcoholic solution to the material and the various solutionsemployed for this purpose should not form too great a roportion of the mass ,of glycerin and gelatin as the latter would then become too thin or fluid.

In place of pyrogallol one can employ other substances, such as metaphenylenediamin, paraphenylenediamin, and particularly those of the phenolroup, for example,

hydroquinone, pyrocatec iin, paramidophenol, diamidophenol chlorid, diamidoresorcinol chlorid, metoquinone (a mixture of 10 parts metol with 3 parts of quinol 6r hydroquinone) adurol (mono-chlor-hydroquinone or mono-brom hydroquinone) eikonogen (sodium Specification of Letters Patent.

Application filed April 24, 1908. Serial No. 429,054..

'means of a thermometer.

amido,8napthol- ,8 'sulfonate), metol (para-methyl-amidm' Patented Aug. 24, 1909.

longer time. The chemical action of these substances on glycerin or glue depends upon the fact that these tanning media take oxygen from the air and. transfer it to the gelatin or glue and thereby render the latter substances insoluble. The gelatin and glue are more dil'li'cult to dissolve in water, in proportion as more oxygen is taken from the air and transferred thereto. This effect can be increased to such-a degree that the gelatin (glue) remains perfectly insoluble even if allowed to lie for hours in boiling water.

7 The process is carriedinto practice in the following manner: 6 kilograms of gelatin powder are steeped in 9 kilograms of glycerin until the mass is quite stifi. These proportions by weight can be altered within certain limits, for example, 4:11, 5:12, 7 8 kilogn, according to the consistency or degree of toughness or viscosity desired and the quality ofthe material emfployed. But if, for example, gelatin of in erior quality is employed, then almost as much gelatin as glycerin can be employed; when using glue one can take more glue than glycerin in order to attain the same efi'ect aswlieri, sinploying the best gelatin'under ,th' 'bove able this temperature to be maintained per-t fectly uniform, the boileris stood in a waterbath, this being effected by-plae ng the boller inside another Vessel. tween the two vessels is filled with water, the temperature of which can be checked by The space left be- When the mass is heated through sufficiently, it is stirred by means of a stirrer for about 1 to 2 hours. By this means, the mass becomes homogeneous, i. e. of perfectly uniform toughness and consistency in all parts, which 1s especially important in order to obtain an ample formation of bubbles, cells or foam. v

The formation of the gelatin into cells or foam can be considerably promoted if very finely pulverized material, such for example, asfinely powdered and sifted ox1d of zinc is (added to -it and stirred in uniformly with the stirrer. This powder does not act chemically, but only physically by affording points for the development of the vapor phase. Bythis means it results that the formation of bubbles or cells begins even 111 the Stirring vessel, which action starts the formation of bubbles or cells, which is to be effected under pressure, considerably more quickl than when the mass is'not previously stirred For the above given quantity of kilograms of material, about 250 grams of finely powdered zinc oxid are'taken. Alsofinely divided insoluble substances in .suspension, e. g. flowers of sulfur suspended in water, are suitable for this purpose.

From the stirring boiler or vessel, the material comes into the foam-beating boiler, in

which it, is to be turned. into foam. This must be so arran ed,'that a high pressure can be producedt ierein, for the higher the pressures under which the mass is beaten, the more aerated and a1so,the lighter will the material be after cooling. A pressure of from 20 to 40 atmospheres is preferably employed (295 to 590 pounds per square inch). However this process of roducing bubbles or foam is not the object oi the present invention. It is. already dealt with in the specipyrogallol are em vent of any strength, and the solution then stirred into the mass. .The quantity of this solution taken should not be too great in order not to dilute the mass-too much and to avoid hydrolysis or hydrolytic cleav'a of the gelatin; on the other hand it must suflicient for the tanning medium to be distributed well throughout all arts of the.

mass. For the above mentione quantity of 20 grams of pyrogallol one takes about 100 grams of water. As however the mixture of gl cerin and gelatin is employed in hot liqul condition at a temperature of about 158 F. and the heat acts to accelerate the tanning process considerably, special precautionary measures must be taken, so that the tanning medium after the mixln does not act too quickly, for after the mixmg-in of 'the'tanmng medium, the mass is to be turned into foam by means of a beatingapparatus. This beating operation lasts from 2 to 5 minutes, assuming that the formation of the foam was previously started by the stirrer. If at this time, the tanning medium acts too quickly, the'consistency or viscosity of the mass becomes too great. This would bevery unfavorable for the formation of foam, as the formation of foam proceeds best at' a definite consistency or gallol instead of 20 grams.

viscosity. The pyrogallol, dissolved in water can therefore be advanta eously introduced into the mass by means 0 a powdery mate? rated with t e solution, is stirred into the mass and'dl ring thebeating gives up the tanning medium to the mass, so that the tanning only begins when the greater part of the am has already been formed.

In cases where the zinc oxid or like ma 'terial is not used, the following proportions may also be employed, the process being otherwise carried into practice as hereinbefore described, viz

Powdered gelatin 360 arts b wei ht. Liquid glycerin 620 P Pyrogallol 4 Infusorial earth 8 lVater 8 i The tanning action can be promoted by mixing alkalies or bromin with the tanning medium. These means cause the. tanning action to take place at a higher rate. They can be employed with those phenols which tan very slowly, but their employment is'excluded infthe case pf those tilliait act .very uickl as or examp e pyroga 0 The tann ing ab tion can also be romoted, withoutincreasing the rate at whic the tanning progresses, by raising the oxy n-content of the air which is forced into ,t 'e beating boiler before the beginning of the beating; in this case however the amount of tanning medium is reduced for the tanning action obviously only lasts 50 long as a sufliresent in the compressed a1r in the 0am.

is absorbed, the further progress of the tannin stops.

-l is process can be carried into practice as follows :First of 'all pure oxygen is forced into the foam-beating boiler, after the latter has been closed, untll the pressure rises to 7% atmospheres pounds per square inch forced in until the pressure rises. to 30 atmospheres (440 pounds per square inch). Then the gaseous mixture in the boiler contains about twice as much oxygen as ordinary air of the same pressure, under which conditions one takes only 10 amsof pyroen, so long as the mass is hot, the subsequent tanning action lasts much longer than when employing ordinary air, since the supply of oxygen in the beaten-in gaseous mixture lasts m'uch lon r than with ordinary air. The rate at which the tannin takes place, which rate would increase i one employed the same quant-it of pyro allol as w en ordmary err is emp'oyed, ist us equalized, when using and after this ordmary air 1s seems air enriched by oxygen, by reducing theamount of tanning medium.

The residue of oxygen in the bubbles can be almost completely utilized'if the bodies, into which the beaten material is introduced, 0. tires, cushions, balls, etc-a after they have been filled, are heated for some hours to about 158 F.

."Vhat I claim is h 1. A process for the manufacture of an elastic cellular or spongy material for-filling tires and for like purposes, consisting-in. soaking gelatin in glycerin, heating the inix-.

ture, adding thereto a tanning material dissolved in a liquid which is carried by an absorbent neutral powder, and beating the mixture into foam with a gas containing oxygen. v

2. A process for the manufacture of an elastic cellular or spongy material for filling tires and for like purposes, consisting in soaking elatin in gylcerin, heating the mix ture, adding thereto a plurality of tanning media of different rates of tanning dissolved in a liquid, and beating the mixture into foam with a gas containing oxygen.

8. A process for, the manufacture of an elastic cellular or spongy materialfor filling tires and for like purposes, consisting in soaking gelatin in glycerin, heating the mixture, adding thereto a very finely powdered material, stlrring the mixture, adding atanning material dissolved in ii liquid, and beatmg; the mlxture into foam'with a gas contaming oxygen.

4. A process for the manufacture of an elastic cellular or spongy material for filling tires and for like purpo s, consisting in soaking gelatin in glyiefifif heating the mixture, adding thereto a anning substance and a substance for accelerating the action of said tanning material, said substances being held in solution in a liquid, and beatin' themixture into foam with a gas containing oxygen. y v

5. A process for the manufacture of an 1 elastic cellular or spongy material for filling I tires and for like purposes, consisting in soaking elatin in glycerin heating the mixture, adding thereto a tanning material dissolved in a liquid, and beating the mixtureinto foam with a gas containing oxygen.

' 6. A process for the manufacture of an elastic cellular or spongy material for filling tires and for like purposes,-consisting"-in producing a homogeneous mixture of gelatin and glycerin, heating the mixture, adding thereto tanning material dissolved in a liquid which is carried by an absorbent neutral powder, beating the mixture into temperature for a suitable time, substan 65.

tially as described.

7. A process for the manufacture of an elastic cellular orspongy material forfilling tires and for like purposes, consisting in producing a homogeneous solution of gelatin inglyc'erin, adding a finely pulverized material thereto, stirrin the mixture in a heated condition, addin thereto tanning v material dissolved in a liquid which is a sorbed by a neutral powdery material, and beating the mixture into a foam with atmospheric air under pressure.

8.-A process for the manufacture of an elastic cellular or spongy material for filling-tires and for like purposes, consisting in soaking powdered gelatin in glycerin,'heating the mixture, stirring the mlxture, adding powdered zinh oxid thereto, adding thereto tanning material dissolved in a liquid which is absorbed by infusorial earth, and beating the mixture into a foam with atmospheric' air under pressure. 1 v

9. A process for the manufacture vof an elastic cellular or spongy material for filling tires and like purposes, consisting in soaking gelatin in glycerin, heating the mixture, beatin the same into foam with compressed air, a ding to said mixture a solution of pyrogallol and a restrainer, and stirring thesaid mixture,

1 10. A process for the manufacture of an 'elastic'cellular or spongy material fonfill ing tires and for like purposes, consisting 1n 9 adding I to said mix 1 's'u'ltant mixture wi --Witnesses:-

soaking gelatin in glycerin, heating the mix} ture, beating the same into foam with-a gas,

' a solution of pyro- 110.

and stirringthe regallol and a restragjher,

h an

In testimony whereof my hand in presence of'two subscribing wit nesses.-

FRITZ PFLEUMER.

PAUL AREAS, Ronnn'r J CALDWELL. 

